[lkml]   [2000]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: refill_inactive()
    On Mon, 25 Sep 2000, Linus Torvalds wrote:
    > On Mon, 25 Sep 2000, Rik van Riel wrote:
    > >
    > > Hmmm, doesn't GFP_BUFFER simply imply that we cannot
    > > allocate new buffer heads to do IO with??
    > No.
    > New buffer heads would be ok - recursion is fine in theory, as long as it
    > is bounded, and we might bound it some other way (I don't think we
    > _should_ do recursion here due to the stack limit, but at least it's not
    > a fundamental problem).
    > The fundamental problem is that GFP_BUFFER allocations are often done with
    > some critical filesystem lock held. Which means that we cannot call down
    > to the filesystem to free up memory.
    > The name is a misnomer, partly due to historical reasons (the buffer cache
    > used to be fragile, and if you free'd buffer cache pages while you were
    > trying to allocate new ones you could cause BadThings(tm) to happen), but
    > partly just because the only _user_ of it is the buffer cache.
    > In theory, filesystems could use it for any other allocations that they
    > do, but in practice they don't, and the only allocations they do in
    > critical regions is the buffer allocation. And as this thread has
    > discussed, even that is really more of a bug than a feature.

    Good thing to have this documented ;)

    "What you're running that piece of shit Gnome?!?!"
    -- Miguel de Icaza, UKUUG 2000

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:45    [W:0.021 / U:4.952 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site